A scientist who investigated public accounts of early Covid-19 cases in China reported Thursday that an influential World Health Organization survey most likely mishandled the early chronology of the pandemic. The new analysis suggests that the first known coronavirus patient was a salesman in a large Wuhana animal market, not an auditor who lived many miles from it.
The report, published Thursday in the prestigious journal Science, will revive, though certainly not resolve, the debate over whether the pandemic began with a spill of wild animals sold at the market, a leak from Wuhan virology lab or otherwise. The search for the origins of the biggest public health disaster in a century has fueled geopolitical battles, with few new facts emerging in recent months to resolve the issue.
The scientist, Michael Worobey, a leading expert on tracking the development of viruses at the University of Arizona, found timeline differences by combining what has already been published in medical journals, as well as video interviews in Chinese news media with people. believed to have the first two documented infections.
Dr. Worobey argues that the vendor’s links to the Huanan Seafood Wholesale Market, as well as a new analysis of the links of the earliest hospitalized patients to the market, strongly suggest that the pandemic began there.
“In this city of 11 million people, half of the early cases are tied to a place that is the size of a football field,” Dr. Worobey said. “It’s very difficult to explain that pattern if the explosion didn’t start at the market.”
Several experts, including one of the pandemic researchers selected by the WHO, said Dr Worobey’s detective work is good and that Covid’s first known case was most likely a seller of seafood.
But some of them also said the evidence is still not enough to decisively resolve the larger question of how the pandemic began. They suggested the virus was likely to infect “patient zero” sometime before the vendor’s case and then reached a critical mass to spread widely in the marketplace. Studies of changes in the genome of the virus – including one done by Dr. Worobey himself – have suggested that the first infection occurred around mid-November 2019, weeks before the vendor fell ill.
“I don’t disagree with the analysis,” said Jesse Bloom, a virologist at the Fred Hutchinson Cancer Research Center. “But I don’t agree that any of the data is strong enough or complete enough to say anything very confident, other than that the Huanan Seafood Market was clearly a super-spreading event.”
Dr Bloom also noted that this was not the first time that the WHO report, conducted in collaboration with Chinese researchers, had been found to contain errors, including errors involving possible links of early patients to the market.
“It’s just a bit impressive that in all of these cases, there are still inconsistencies about when that happened,” he said.
“The Error Lies There”
In late December 2019, doctors at several Wuhan hospitals noticed mysterious cases of pneumonia that appeared in people working at the Huanan Seafood Wholesale Market, a damp and poorly ventilated area where seafood, poultry, meat and wildlife were sold. On December 30, public health officials told hospitals to report any new cases related to the market.
Fearing a recurrence of SARS that emerged from Chinese animal markets in 2002, Chinese officials ordered the Huanan market to close, and Wuhan police closed it on January 1, 2020. Despite these measures, new cases have proliferated across Wuhan.
Wuhan authorities said on January 11, 2020 that cases began on December 8. In February, they identified the earliest patient as a resident of Wuhan with the family name Chen, who fell ill on December 8 and had no connection to the market. .
Chinese officials and some outside experts suspected that the initially high percentage of cases linked to the market may have been a statistical coincidence known as ascertaining bias. They argued that the Dec. 30 call by officials to report market illnesses may have led doctors to overlook other cases without such links.
“At the outset, we assumed that the seafood market may have the new coronavirus,” said Gao Fu, director of China’s Center for Disease Control and Prevention, in May 2020, according to China Global Television Network. “But now it turns out the market is one of the victims.”
By the spring of 2020, senior members of the Trump administration had announced another scenario for the origin of the pandemic: that the virus had escaped from the Wuhan Institute of Virology, which has a campus about eight miles away from the Huanan market, across the Yangtze River. .
In January of this year, researchers selected by the WHO visited China and interviewed an accountant who reportedly developed symptoms on December 8th. Their influential report of March 2021 described him as the first known case.
But Peter Daszak, a disease ecologist at EcoHealth Alliance who was part of the WHO team, said he was convinced by Dr Worobey’s analysis that they were wrong.
“That December the eighth date was a mistake,” Dr. Daszak said.
La A WHO team has never asked the accountant the date since his symptoms began, he said. Instead, they were given the date of December 8 by doctors from Hubei Xinhua Hospital, who treated other early cases but did not care for Mr. Chen. “So the mistake lies there,” Dr. Daszak said.
For the WHO experts, Dr Daszak said, the interview was a dead end: The accountant had no apparent links to an animal market, laboratory or rally. He told them he likes to spend time on the internet and jogging, and he didn’t travel much. “He was as vanilla as you could get,” Dr. Daszak said.
If the team identified the seafood vendor as the first known case, Dr. Daszak said, it more aggressively dealt with questions like in which booth she worked and where her products came from.
This year, Dr. Daszak was one of the strongest critics of laboratory leak theory. He and his organization, EcoHealth Alliance, took heat for research collaborations with the Wuhan Institute of Virology. Last month, the National Institutes of Health said EcoHealth had violated the terms of its grant for research on coronaviruses in bats.
While the doctors of the Hubei Xinhua Hospital said that the beginning of the accountant’s illness was on December 8, a senior doctor from Wuhan Central Hospital, where Mr. Chen was treated, told Chinese news media that he had developed symptoms around December 16th. .
Asked about Mr. Chen’s case, China’s National Health Commission said it supports comments made by Liang Wannian, the leader of the Chinese side of the WHO-China investigation who led the interview with the doctors of Hubei Xinhua Hospital. . Mr. Liang said in a press conference in February this year that Covid’s earliest case showed symptoms on December 8 and “was not tied” to the Huanan market.
Errors and Inconsistencies
In their report, the WHO experts concluded that the virus was most likely to spread to humans due to animal spread, but they could not confirm that the Huanan market is the source. In contrast, they said a lab leak was “extremely unlikely.”
The report has been criticized for several errors and omissions. The Washington Post revealed in July that the report listed the wrong virus samples for several early patients – including the first official case – and erroneously linked the first family set of cases to the Huanan market. The WHO has promised to fix the errors, but they remain in the report on the organization’s website. (The organization said it would ask the report’s authors if and how they would correct the errors.)
In May, two months after the publication of the WHO and China report, 18 eminent scientists, including Dr. Worobey, responded with a letter in Science complaining that the WHO team had shortened the theory of laboratory leakage. Much more research was required, they argued, to determine whether one explanation is more likely than the other.
An expert on the origins of influenza and HIV, Dr. Worobey attempted to put together the early days of the Covid pandemic. Reading a May 2020 study of early cases written by local doctors and health workers in Wuhan, he was confused to see a description that looked like Mr. Chen: a 41-year-old man with no contact with the Huanan market. But the study’s authors dated his symptoms to Dec. 16, not Dec. 8.
Then Dr. Worobey found what appeared to be a second, independent source for the later date: Mr. Chen himself.
“I had a fever on the 16th, during the day,” a man identified as Mr. Chen said in a March 2020 video interview with The Paper, a Shanghai-based publication. The video indicates that Mr. Chen is a 41-year-old who worked in a company’s financial office and never went to the Huanan market. Official reports said he lives in Wuchang district in Wuhan, miles from the market.
The New York Times could not independently confirm the man’s identity in the video.
Along with his fever on December 16, Mr. Chen said he felt pressure in his chest and went to the hospital that day. “Even without any strenuous exercise, with just a little effort, like how I’m talking to you now, I would feel lacking,” he said.
Dr Worobey said the medical records shown in the video could have indications of how the WHO-China report ended with an incorrect date. One page described surgery Mr. Chen needed to remove teeth. Another was a December 9 prescription for antibiotics related to a fever from the previous day – possibly the day of the dental surgery.
In the video, Mr. Chen speculated that he may have received Covid “when I went to the hospital” – perhaps a reference to his earlier dental surgery.
The Washington Post noted in July that the details provided by the WHO for the Dec. 8 case seemed to match better with an entry from an online database of virus samples linked to someone who fell ill on Dec. 16. In response, the WHO had said it was investigating the difference.
An agency spokesman told The New York Times that it would be “difficult to comment” on the first known case because the WHO team had limited access to health data. He said it is important for researchers to continue to look for infected patients even earlier.
In Dr. Worobey’s revised chronology, the earliest case is not Mr. Chen but the seafood seller, a woman named Wei Guixian, who developed symptoms around December 11th. (Ms. Wei said in the same video published by The Paper that her serious symptoms began on December 11, and she told The Wall Street Journal that she began to feel ill on December 10. The report of WHO-China listed a December 11 case related to the market.)
Dr. Worobey found that hospitals reported more than a dozen probable cases by Dec. 30, the day the Wuhan authorities alerted doctors to pay attention to links to the market.
He determined that Wuhan Central Hospital and Hubei Xinhua Hospital each recognized seven cases of unexplained pneumonia by December 30, which would be confirmed as Covid-19. In each hospital, four out of seven cases were linked to the market.
Concentrating only on these cases, Dr. Worobey argued, he could rule out the possibility that a observed bias tipped the results in favor of the market.
However, other scientists have said it is not clear that the pandemic started at the market.
“He’s done an excellent job of reconstructing what he can from the available data, and it’s as reasonable a hypothesis as any,” said Dr. W. Ian Lipkin, a virologist at the Post Office School of Public Health at Columbia University. “But I think we’ll never know what’s going on because it’s been two years and it’s still unclear.”
Alina Chan, a postdoctoral fellow at the Broad Institute in Cambridge, Mass., And one of the most vocal proponents of laboratory leak research, said only new details of earlier cases – going back to November – would help scientists trace the origin.
“The main thing that draws attention to this,” she said, “is that there is a lack of access to data, and there are errors in the WHO-China report.”
Eleanor Goodman contributed translation and Liu Yi contributed research.